1. Technical Field
The present invention relates to a liquid crystal apparatus and electronic equipment.
2. Related Art
A liquid crystal apparatus is provided with a liquid crystal panel in which a liquid crystal layer is interposed between a pair of substrates. When light is incident to such a liquid crystal apparatus, the liquid crystal material, alignment film, or the like which forms the liquid crystal panel undergoes a photochemical reaction due to the incident light and ionic impurities may be generated as a reaction product. In addition, it is known that ionic impurities also diffuse into the liquid crystal layer from sealing material or a sealant in the manufacturing process of the liquid crystal panel. In particular, in a liquid crystal apparatus used in an optical modulating means (light valve) of a projection-type display apparatus (projector), since the luminous flux density of the incident light is high in comparison with a direct-view-type liquid crystal apparatus, it is necessary to suppress the ionic impurities from influencing the display.
As a means for suppressing the influence of the ionic impurities on the display, for example, JP-A-2015-1634 proposes a driving method for arranging three electrodes (ion trap electrodes) on the outer peripheral section of the display region and applying alternating current signals with different phases in a time equivalent to one period.
According to the driving method of JP-A-2015-1634, a transverse electric field is generated between the three electrodes and force for moving the ionic impurities is exerted from the display region toward the outer peripheral section of the display region in addition to the flow according to minute fluctuations in the liquid crystal. Therefore, since it is possible to efficiently accumulate ionic impurities in a region provided with the outermost peripheral electrode out of the three electrodes described above, it is possible to provide a liquid crystal apparatus with reduced display defects such as burn-in caused by ionic impurities.
However, in the liquid crystal apparatus described in JP-A-2015-1634, the liquid crystal apparatus is driven by turning on the power, and ionic impurities moving from the display region to the outer peripheral section of the display region are accumulated in the region in which the outermost peripheral electrode is provided; however, thereafter, there is a concern that the ionic impurities accumulated during the driving will be diffused in concentration and return to the display region when the power of the liquid crystal apparatus is turned off.
From the above, there is a problem in that the influence of the ionic impurities included in the liquid crystal layer on the display may not be sufficiently suppressed.